The UMTS, third generation of wireless communications systems, that is being added to 2nd generation of wireless communications systems (such as GSM900, DCS, PCS1900, CDMA, TDMA) has created a demand for multiband antennas and in particular to Dual Band Base Station Antennas. The typical Dual band antennas that are used today are side by side arrays where the size is typically twice of the size of a single band antenna. To be more specific the typical width of Dual Band antenna is around 2 wavelengths, which is about 30 cm in the case of an antenna operating at two of the following communication services DCS, PCS or UMTS while the width of a Single Band antenna is typically around one wavelength, which is around 15 cm in case of a DCS, PCS or UMTS antenna.
The cellular services require several Base Stations that are composed by several base station antennas to give service to the cellular users. The antennas are the radiating part of the Base Station. Typically, the radiating part of the Base Station is composed by nine or three independent antennas that give coverage to a specific part of the city, village, road, motorway. As the radiating part of the Base Station is composed by several antennas, the size of the Base Station is large and has a significant visual impact.
The visual impact due to the size and number of antennas at the Base Station has been a rising issue for operators and consumers, so creating a demand for smaller antennas, having less visual impact, but still maintaining the same performance and functionality. Governments desire to minimize the visual impact of the Base Station, and it is becoming very difficult for the operators to get a license to set up new Base Stations on the cities and villages around the world.
Adjustable electrical down-tilt techniques for antenna systems are very well known in the related background art.